Accurate Resonance-Parameter Approach to Transition-Metal Band Structure

The position Ed and width W of the d resonance are shown to be good physical parameters, in that the same pair of parameters (Ed=0.540, $W=0.088$ Ry) is capable of reproducing Wood's band structure of fcc and bcc iron to within a rms error of 0.006 Ry. The energy levels were obtained by diagonalizing an improved hybrid nearly-free-electron tight-binding model Hamiltonian that includes explicitly the nonorthogonality of the basis functions.